The soundsets are in the correct places.
The first image I attached shows what the Playback Configuration's Sibelius Player instance should look like, with the S7S-SE6 SoundSet applied. Second image shows the choices in the dropdown once you double click the field in that column.
From there, find the .sib file from the Bundle package labeled "S7S-SE6_Bundle_7.1a_(Sib7).sib", make a copy of it
for each project you start, or follow the instructions in Appendix C of any of the Readme files to Export Manuscript Paper
Then, once you have a copy of the .sib file open, the third image shows the S7S and SE6 Templates in the Choose from
dropdown, of which you'll want to select instruments from these to use in your score/project.
Let me know if you have further questions.